Suction apparatus



Oct. 30, 1934. F. L., BARsTow SUCTION APPARATUS Filed Feb. l1, 1955INVENTo @l ATTORN Patented Oct. 30, 1934 SUCTION APPARATUS Francis L.Barstow, Springfield, Mass., assgnor to New York Belting & PackingCompany, Passaic, N. J., a corporation of New York Application February11, 1933, Serial No. 656,239

12 Claims.

My invention relates to suction apparatus, and more particularly tosuction rolls for use in paper making machinery for extracting moisturefrom pulp on a porous conveyor, such as a felt belt.

5 In the manufacture'of paper it is customary practice to convey thepulp from the Fourdrinier wire or other sheet forming devices throughpressure rolls, commonly called presses, to drying drums for theextraction of liquids. Such press l rolls are arranged in pairs, theupper roll usually having a polished continuous surface. Various metals,rubber, wood, stone and composite material may be used for such rolls.The lower roll f is frequently provided with means for removing lmoisture from the pulp by the application of a vacuum.

One form of lower pressure roll which is frequently used is a metalshell supported at its ends by heads resting in bearings. The shell isprovided with perforations which rotate past a stationary suction box.The suction box is disposed adjacent the area of engagement between theupper and lowerKrolls sov that'the suction is applied to the area of thelower roll in cooperative engagement with the yupper roll at any time.

'I'he outer cylindrical surface of the shell is preferably provided witha layer of relatively soft material 'such as rubber. The thickness ofthis coating may be of the order of one inch. 'I'his 'outer surface isalso perforated so that the pulp carrying conveyor disposed between thetwo rolls is subject to a vacuum for withdrawing liquids from the pulpon the conveyor. The porous conveyor belt is frequently driven by thebite of the rolls. 'This also provi`des pressure for forcing the liquidsfrom the pulp and for compacting the pulp.

Heretofore considerable diiculty has been encountered in the manufactureof perforated coated press rolls. The shell proper has usually been madeof metal which is perforated with a. great many smaller holes of theorder of of an inch in diameter on circumferential and Widthwise centersof the order of it; to 1% of an inch. The

drilling of such holes offers no particular diiiiculty. However, whenthe covering is applied, particularly in the case of a rubber covering,it isfin the f rm of a continuous sheet which extends over/and closesthe openings in the underlying metal. Thereafter it is necessary tosepa- 'rately drill the openings in the covering. The problem ofsecuring registry between the openings in the covering and those in theunderlying metal of the shell is extremely diicult, even in themanufacture of new rolls. Where it is desired to recover a used roll,the problem of securing registry is much more difficult. In manyinstances it is desired to recover the roll at a factory or plant otherthan vthat of the original manufacturer of the roll. In such a case itis rst necessary to secure from the original manufacturer of the roll anindex of the drilling of the openings in the metal roll or tolaboriously plot them. Because of these conditions the papermanufacturer usually takes the roll out of service and ships it to themanufacturer.

I provide suction apparatus in which the coating is separable from themetal shell so that the replacement /of the coating does not take themetal shell out of service for a great length cf time, nor does itrequire that the shell be sent to a specially equipped factory. Byproviding the coating in the form of a belt having a length considerablyin excess of the circumference of the roll and by providing perforationsin the belt and then running the belt between the pulp conveying beltand the metal shell as the latter rotates, suction is eifectivelyapplied to the pulp. Preferably the openings in the belt at the shellengaging surface are of greater diameter than are the openings in theshell. If desired the outer ends of the shell openings and the innerends of the conveyor openings may be flared. Also the number of openingsin the belt may be in excess of the number of openings inthe shell. Ineither or both cases a sucient number of the belt openings will be inregistry with the shell openings to insure the application of a vacuumto the porous pulp conveyor which is momentarily supported by the lowerpress roll;

Provision is made for Atensioning and guiding the perforated belt.Provision is also made for cleaning the porous belt of particles of pulpor other material which may be carried by it.

The accompanying drawing illustrates a present preferred embodiment ofmy invention, in which Figure 1 is a diagrammatic view, partially inelevation and partially in section, of the suction apparatus embodyingmy invention;

Fig. 2 is a cross sectional view of a portion of 100 the shell andperforated belt;

Fig. 3 is a broken plan view of a portion of the shell and perforatedbelt; and

Fig. 4 is an elevational view of adjusting and guiding apparatus for theperforated belt.

Referring to the drawing, a porous conveyor belt 1, generally of felt,is advanced by driving rolls 2 for engaging a partially dried sheet ofpulp 4. The porous conveyor belt 1 and the sheet 4 are fed between anupper or top press roll 5 and 110 order of 4/l0 to 5/10 of an inch. Itis to be understood that these values are exemplary and are not to beconsidered limitations of the invention ing the rubber to the asdifferent manufacturers use different sizes and spacings of openings.The shell 7 is mounted in brackets 9 by stub shafts l0 extending fromheads 11. One of the heads may be provided with a gear 12 for rotatingit. The conveyor belt l is advanced by the bite of the rolls 5 and 6.

A stationary suction box 14 is mounted within the shell 7 by supportingarms 15 which may extend outwardly from one or both of the stub shafts10. A flexible pipe line (not shown) may be attached to one of the stubshafts for applying vacuum to the interior of the suction box 14 througha channel or channels in the arm or arms v15. 'Ihe details of theseconnections are 'well known in the art, for which reason a fulldescription is omitted from the present specification.

For providing a cushioning surface between the conveyor belt 1 and themetallic surface of the shell 7, which is oftenof bronze, I provide aperforated belt 16 of flexible material such as rubber. Where rubber'isused as the material for the belt 16 it should be cured and may be ofthe same general characteristics as rubber covers now used on suchrolls. However, due to the elimination for the need of permanentlyattachmetal of the shell 7 the thickness is materially reduced. Thisalso eliminates the need for specially bonding the coating surface tothe shell 7 which has heretofore been a very difcult and costlyoperation. The rubber coatings permanently attached now normally usedare of the order of 111g inches in thickness including the bondinglayers and the outer cushioning layers. The belt 16 may be of the orderof H of an inch in thickness which is a common thickness for acushioning rubber. Openingsl' are provided in the belt 16 forcooperation with the openings 8 in the shell 7. To this end the outerends 18 of the openings 8 may be ared to cooperate with flares 19 at theinner ends of the openings 17. The sizes and spacings of the openings 17may be the same or vary slightly from the sizes and spaces of theopenings 8 as the provisions of the flaring ends of these sets ofopenings insures that, regardless of the relative positions of the shell7 and the belt 16, there will be a sufcient'number in contact to insurethe application of a vacuum in that portion of the belt 16 outside ofthe suction box 14.

Because of the tendencyvfor slippage between the shell 7 and the belt 16owing to the driving force transmitted to the porous conveyor belt l, itis desirable to tension the belt 16 and insure that it lhas a suiiicientfrictional engagement with the shell 'l to prevent slippage. 'Ihis maybe accomplished by causing the belt 16 to engage the surface of theshell 7 throughout a large angle, an engagement of substantially 240being shown in Fig. 1. Also a tensioning roll 20 may be mounted inbrackets 21 having adjustment screws 22 'and 24 for tensioning the belt16. Flanges 25 are provided at`the ends of the roll 20uto prevent thebelt 16 from running oi the ro In order `to remove particles of pulp,lint, and the like, from the belt 16, a spray line 26 may be providedfor washing the belt. An air blast may be used in lieu of the spray 26.The spray 26 is preferably placed internally of the beltl6 so as to washthe refuse outwardly through the openings 17 and thus rid the belt ofit. A catch basin 27 may be provided for removing the wash Water and therefuse.

Referring to Fig. 4 for positioning jthe 'belt 16 with respect to theshell 7, I may prov1de positive guiding means in lieu of the tensionroll 20 shown in Fig. l. To this end I provide a guide flnger 28 whichis stationarily mounted on a bed 29. An adjustable finger 30 on the bed29 is controlled by a screw 31 extending through a boss 32. By adjustingthe relative positions of the fingers 28 and 30 various widths of beltmay be guided. For positioning the bed 29 relative to the shell 7, Iprovide a base 34 having a way 35 for the bed 29. A screw 36 operated byhandwheel 37 enters a threaded bore 38 in the bed 29 for adjusting itlaterally with respect to a boss 39 on the base 34.

If desired, the guiding apparatus shown in Fig. 4 may be used inconjunction with the tensioning roll 20, or the tensioning roll 20 maybe given lateral adjustment.

With the apparatus of the present invention 'the need for accuratedrilling of openings in a rubber or other soft covering for a suctionroll is eliminated, since the covering of the present invention is inthe form of a from a permanent covering vulcanized or otherwise fastenedto the shell 7. 'llihe dispositioning of the perforations 17 in the belt16 is such that a sumcient number of them will be in a co-operativecontact with perforations 8 at the suction box 14 to effectivelywithdraw the moisture from the belt 1. This construction also eliminatesthe need for removing the shell 7 from a paper mill and transporting ita considerable distance to have it recovered.

While I have shown and described the present preferred embodiment of theinvention in connection with paper machinery, it is to be understoodthat the invention may be otherwise utilized and embodied within thespirit of the invention and the scope of the appended claims.

Having thus described my invention, what I claim and desire to protectby Letters Patent is:

1. In suction apparatus, the combination with a movable surface havingings therein, andy means for applying a condition of vacuum to the innerends of said openings, of a separable cushioning layer havingperforations flaring outwardly toward the flared perforations in saidsurface whereby a condition of vacuum is transmitted through saidsurface and cushioning body without requiring perfect registry of theopenings therein.

2. In suction apparatus, a support having a plurality of openingsextending therethrough, means for applying a condition of vacuum tocertain of said openings, and a separable cushioning body engaging aportion of the surface of said support, said cushioning body havingopenings extending therethrough of suicient number and shape to transmitthe condition of vacuum from thelsupport to the outer surface thereofwithout requiring precise registry of the openings in said support landcushioning body.

3. In suction apparatus, a support having a belt as distinguishedoutwardly flared opensu-flicient number and shape to transmit thecondition of vacuum to the outer surface thereof Without requiringprecise registry of the openings in said support and cushioning body.

- v 4. The combination with a yperforated metallic press roll, of aperforated rubber cushioning belt the cushioning belt.

fortransmitting a condition of vacuum from the interior of the roll .tothe exterior surface of 5. 'I'he combination with a perforated bottompress roll, and means for applying a condition of vacuum to at least Vaportion of the interior of said roll, of a separable, perforated rubbercushioning belt directly engageable with a portion of the outer surfaceof said roll for carrying material traversing a pair of press rolls andapplying 'a condition of vacuum thereto.

6. The combination with a perforated press roll for a paper machine, andmeans for applying a condition of vacuum to at least a portion of theinterior of said roll, of a separable, perforated rubber cushioning beltdirectly engageable with a portion of the outer surface of said roll forcarrying material traversing a pair of press rolls and applying acondition of vacuum thereto.

7. A belt for a suction device having a plurality of openings therein,the .openings at one face of the belt occupying a larger area of thebelt than at the opposite face.

8. Thev combination with a perforated press roll, and means for applyinga condition of vacuum thereto, of a perforated rubber cushioning belthaving openings for cooperation withthe perforations in said roll fortransmitting the conL dition of vacuum, and means for tensioning andguiding the belt.

9. The combination with a roll having perforations for the transmissionof a condition of vacuum, and a separable conveyor having vacuumtransmitting perforations for cooperation with those of the roll, ofmeans cooperating with a portion of said conveyor separated from saidroll for removing foreign matter.

10. 'I'he combination with a roll having perforations for thetransmission of a condition of vacuum, and a separable conveyor havingvacuum transmitting perforations for cooperation with those of the roll,of a spray for cooperating with a portion of said conveyor separatedfrom said roll for removing foreign matter.

11. 'Ihe combination with a roll having perforations vfor thetransmission of a condition of vacuum and a separable conveyor havingvacuum transmitting perforations for cooperation with those of the roll,of a spray disposed internally of a position of the conveyor separatedfrom said roll for removing foreign matter.

12. The combination with a roll having perforations for the transmissionof a condition of vacuum and a separable conveyor having vacuumtransmitting perforations for cooperation with those of the roll, of aspray disposed internally of a portion of the conveyor separated fromsaid roll for removing foreign matter, and a catch basin for conveyingthe washings away from the

